<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>my css</title>
    <style>
        body {
            background: silver;
            color: blue;
        }
        hr {
            color: red;
        }
    </style>
</head>
<body>
<h2>2号标题</h2>
<hr>
达内云计算 cloud computing
</body>
</html>